For all their vaunted status and multiple millions they sell for these days, Ferraris were once used cars – yesterday’s news with an engine that in many cases proved a liability rather than another part of the mystique. So while an engine swap in any other car’s past might make for a curiosity, engine-swapped Ferraris qualify for a class all their own at this year’s Concorso Italiano.

As Randy Cook, author of two books devoted specifically to engine-swapped Ferraris – Bowtie Ferraris and Blue Oval, et al, Ferraris – noted, not every vintage Ferrari owner likes to admit that his car once relied on something as common as a Chevrolet or Ford V-8 for power. “Some people do, though some don’t want the notoriety,” he said. “Even when it’s public knowledge, some don’t want it to be publicized.”

Yet Cook has documented 99 instances in which former owners ditched the original Ferrari engine for one either more powerful, more reliable, or more easily serviced: 76 of them using Chevrolet engines, 14 using Ford engines, four using Buicks, two using Offenhausers, and one each using a Chrysler, Mercedes, and Maserati engine. Pretty much all of them occurred in the mid-Fifties through late 1960s.

Cook said he believes still more engine-swapped Ferraris remain undocumented. “My guess is that every one that went to South America had an American engine in it at one point,” he said.

Generally, Cook said, owners of street-driven Ferraris chose to repower their cars following a failure of the original engine. As for Ferraris dedicated to racing, about half got repowered following an engine failure, the rest because another engine was cheaper to maintain or because another engine proved more competitive.

“For example, they could still run the same class with a 5.0-liter Chevrolet engine that they previously ran with the original 3.0-liter Ferrari engine,” Cook said.

Ferrari serial number 0235.

Noteworthy examples of Ferraris that once relied on something other than Ferrari power include 0666, the first 250 Testa Rossa, which famously sold for $16 million five years ago (and which had a Ford V-8 installed in the mid-1960s); and 0235, a 212 Inter Pinin Farina cabriolet displayed at Paris and Brussels when new (and which later received a Chevrolet V-8).

Almost every engine-swapped Ferrari returned to Maranello power during the price bubble of the late 1980s and early 1990s, largely thanks to collector Dick Merritt, who stockpiled at least two dozen removed Ferrari engines during the years prior. Cook said that, to his knowledge, only one Ferrari remains with its swapped engine still underhood: serial number 1175, the 1959 250 GT Series 1 Pinin Farina coupe that he once owned and that inspired the Concorso class when Tom McDowell spotted it at last year’s event.

Perhaps due to the reluctance of current-day Ferrari owners to address the engine-swap history of their cars, Cook said he and McDowell are still searching for examples to fill the class. Among those slated to appear are the above mentioned serial number 0235 and serial number 0438, a 1954 500 Mondial once powered by a 320hp Corvette V-8.

Concorso Italiano takes place August 20 at Black Horse Golf Course in Monterey Bay, California. For more information, visit Concorso.com.